Hydrangea plant named ‘H217905’

ABSTRACT

A new and distinct cultivar of Hydrangea plant named ‘H217905’, characterized by its upright and rounded plant habit; vigorous growth habit and rapid growth rate; freely branching habit with strong, thick and sturdy stems; early, freely and uniformly flowering habit; mophead-type inflorescences with numerous intense red purple-colored sterile flowers; and good postproduction longevity.

Botanical designation: Hydrangea macrophylla.

Cultivar denomination: ‘H217905’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Hydrangea plant, botanically known as Hydrangea macrophylla, commercially referred to as a mophead-type Hydrangea and hereinafter referred to by the name ‘H217905’.

The new Hydrangea plant is a product of a planned breeding program conducted by the Inventor in De Kwakel, The Netherlands and Glandorf, Germany. The objective of the breeding program was to create new compact and freely-branching Hydrangea plants with strong sturdy stems, large inflorescences with numerous showy sterile flowers, attractive sterile flower color and good postproduction longevity.

The new Hydrangea plant originated from a cross-pollination made by the Inventor in March, 2012 in De Kwakel, The Netherlands, of two unidentified proprietary selections of Hydrangea macrophylla, not patented. The new Hydrangea plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination in a controlled greenhouse environment in Glandorf, Germany in March, 2013.

Asexual reproduction of the new Hydrangea plant by vegetative tip cuttings in a controlled environment in De Kwakel, The Netherlands since April, 2014 has shown that the unique features of this new Hydrangea plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Hydrangea have not been observed under all possible combinations of environmental conditions and cultural practices. The phenotype may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘H217905’. These characteristics in combination distinguish ‘H217905’ as a new and distinct Hydrangea plant:

-   -   1. Upright and rounded plant habit.     -   2. Vigorous growth habit and rapid growth rate.     -   3. Freely branching habit with strong, thick and sturdy stems.     -   4. Early, freely and uniformly flowering habit.     -   5. Mophead-type inflorescences with numerous intense red         purple-colored sterile flowers.     -   6. Good postproduction longevity.

Plants of the new Hydrangea can be compared to plants of the female and male parent selections. Plants of the new Hydrangea differ primarily from plants of the female and male parent selections in plant habit as plants of the new Hydrangea are more compact than plants of the female and male parent selections.

Plants of the new Hydrangea can be compared to plants of the Hydrangea macrophylla ‘H213906’, disclosed in U.S. Plant Pat. No. 26,509. In side-by-side comparisons, plants of the new Hydrangea differ primarily from plants of ‘H213906’ in the following characteristics:

-   -   1. Panicles of plants of the new Hydrangea are smaller than         panicles of plants of ‘H213906’.     -   2. Plants of the new Hydrangea have more sterile flowers per         inflorescence than plants of ‘H213906’.     -   3. Plants of the new Hydrangea and ‘H213906’ differ in reaction         to aluminum sulfate treatment as sterile flower sepals of plants         of the new Hydrangea treated with aluminum sulfate become light         blue in color whereas sterile flower sepals of plants of         ‘H213906’ treated with aluminum sulfate become violet blue in         color.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the unique appearance of the new Hydrangea plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ from the color values cited in the detailed botanical description which accurately describe the colors of the new Hydrangea plant.

The photograph on the first sheet is a side perspective view of a typical flowering plant of ‘H217905’.

The photograph on the second sheet is a top perspective view of a typical flowering plant of ‘H217905’.

The photograph on the third sheet is a close-up view of a typical inflorescence of ‘H217905’ that has not been “blued”, that is, not treated with aluminum sulfate.

The photograph on the fourth sheet is a top perspective view of a typical flowering plant of ‘H217905’ that has been “blued”.

DETAILED BOTANICAL DESCRIPTION

Plants used in the aforementioned photographs and in the following description were grown during the late spring and early summer in 13-cm containers in a glass-covered greenhouse in De Kwakel, The Netherlands and under cultural practices typical of commercial Hydrangea production. During the production of the plants, day and night temperatures averaged 17° C. Plants of the new Hydrangea one year old when the photographs and description were taken. Plants of the new Hydrangea can be successfully treated with aluminum sulfate to “blue” the inflorescences. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2015 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical description: Hydrangea macrophylla ‘H217905’. -   Parentage:     -   -   Female, or seed, parent.—Unidentified proprietary selection             of Hydrangea macrophylla, not patented.         -   Male, or pollen, parent.—Unidentified proprietary selection             of Hydrangea macrophylla, not patented. -   Propagation:     -   -   Type cutting.—By vegetative tip cuttings.         -   Time to initiate roots, summer.—About two weeks at             temperatures about 23° C.         -   Time to initiate roots, winter.—About 18 days at             temperatures about 20° C.         -   Time to produce a rooted young plant, summer.—About four             weeks at temperatures about 23° C.         -   Time to produce a rooted young plant, winter.—About five             weeks at temperatures about 20° C.         -   Root description.—Thick; typically whitish brown in color,             actual color of the roots is dependent on substrate             composition, water quality, fertilizer type and formulation,             substrate temperature and physiological age of roots.         -   Rooting habit.—Freely branching; dense. -   Plant description:     -   -   Plant and growth habit.—Upright and rounded plant habit;             strong and sturdy stems; rapid growth rate and vigorous             growth habit.         -   Plant height.—About 25 cm to 35 cm.         -   Plant diameter or area of spread.—About 40 cm. -   Lateral branch description:     -   -   Branching habit.—Freely branching habit; when pinched, about             eight lateral branches develop per plant.         -   Length.—About 20 cm to 25 cm.         -   Diameter.—About 6 mm.         -   Internode length.—About 3 cm to 4 cm.         -   Texture.—Smooth, glabrous; fully developed, woody.         -   Aspect.—Upright to about 20° from vertical.         -   Strength.—Strong, sturdy.         -   Color.—When developing: Close to 146C; at internodes, close             to 187A; lenticels, close to 187A. Developed: Close to 146C;             at the internodes, close to 187A; when woody, close to 177C;             lenticels, close to 187A. -   Leaf description:     -   -   Arrangement.—Opposite, simple.         -   Length.—About 8 cm to 10 cm.         -   Width.—About 6.5 cm to 7 cm.         -   Shape.—Ovate.         -   Apex.—Acute.         -   Base.—Obtuse.         -   Margin.—Dentate to serrate.         -   Texture, upper surface.—Smooth to rugose, glabrous.         -   Texture, lower surface.—Rugose, glabrous.         -   Venation pattern.—Pinnate.         -   Color.—Developing leaves, upper surface: Close to 139A.             Developing leaves, lower surface: Close to 137D. Fully             developed leaves, upper surface: Close to 139B; venation,             close to 145B. Fully developed leaves, lower surface: Close             to 137C; venation, close to 145C.         -   Petioles.—Length: About 2 cm. Diameter: About 5 mm. Texture,             upper and lower surfaces: Smooth, glabrous. Color, upper and             lower surfaces: Close to 145C. -   Flower description:     -   -   Flower type and habit.—Showy sterile flowers and small             inconspicuous fertile flowers arranged on mophead-type             terminal panicles; panicles globular in shape; flowers face             upright to outwardly depending on their position in the             inflorescence.         -   Fragrance.—None detected.         -   Natural flowering season.—Early flowering habit, plants             begin flowering about three months after planting; flowering             begins in the early summer and is continuous throughout the             summer in Northern Europe.         -   Flower longevity.—Fertile flowers last about one month on             the plant, fertile flowers not persistent; sterile flowers             last about four months on the plant, sterile flowers             persistent.         -   Quantity of flowers.—Freely flowering habit; about 25 to 30             fertile flowers per panicle and about 76 sterile flowers per             panicle.         -   Panicle height.—About 8 cm to 10 cm.         -   Panicle diameter.—About 13 cm to 14 cm.         -   Fertile flower buds.—Length: About 3 mm. Diameter: About             3 mm. Shape: Rounded. Color: Close to 145C.         -   Sterile flower buds.—Length: About 3 mm. Diameter: About             3 mm. Shape: Rounded. Color: Close to 145C.         -   Fertile flower diameter.—About 6 mm.         -   Fertile flower depth (height).—About 6 mm.         -   Sterile flower diameter.—About 3.5 cm to 4.5 cm.         -   Sterile flower depth (height).—About 1 cm to 1.5 cm.         -   Petals, fertile flowers.—Quantity and arrangement: Five in a             single whorl. Length: About 3 mm to 4 mm. Width: About 2 mm.             Shape: Ovate. Apex: Acute. Base: Cuneate. Margin: Entire.             Texture, upper and lower surfaces: Smooth, glabrous. Color:             When opening, upper and lower surfaces: Close to 145C. Fully             opened, upper and lower surfaces: Close to 75B; color does             not change with development.         -   Petals, sterile flowers.—Petal development has not been             observed on sterile flowers of plants of the new Hydrangea             to date.         -   Sepals, fertile flowers.—Quantity and arrangement: Five in a             single whorl. Length: About 2 mm. Width: About 2 mm. Shape:             Ovate. Apex: Acute. Base: Obtuse. Margin: Entire. Texture,             upper and lower surfaces: Smooth, glabrous. Color: When             opening, upper and lower surfaces: Close to 145B. Fully             opened, upper and lower surfaces: Close to 155D; color does             not change with development.         -   Sepals, sterile flowers.—Quantity and arrangement: Four in a             single whorl. Length: About 1.5 cm to 2.5 cm. Width: About 2             cm to 2.5 cm. Shape: Deltoid. Apex: Acute to obtuse. Base:             Cuneate. Margin: Entire to crenate. Texture, upper and lower             surfaces: Slightly rugose, glabrous. Color: When opening,             upper and lower surfaces: Close to 144D. Fully opened, upper             surface: Close to 72C; when “blued”, close to 100B; colors             do not change with development. Fully opened, lower surface:             Close to 75B; when “blued”, close to 100D; colors do not             change with development.         -   Pedicels, fertile flowers.—Length: About 5 mm. Diameter:             About 1 mm. Strength: Strong. Aspect: Mostly upright.             Texture: Smooth, glabrous. Color: Close to 75B.         -   Pedicels, sterile flowers.—Length: About 2.5 cm. Diameter:             About 2 mm. Strength: Strong. Aspect: Erect to about 45°             from vertical. Texture: Smooth, glabrous. Color: Close to             75B.         -   Reproductive organs, fertile flowers.—Stamens: Quantity per             flower: Eight. Filament length: About 1 mm. Filament color:             Close to 76B. Anther length: About 1 mm. Anther shape:             Conical. Anther color: Close to 76A. Pollen amount:             Abundant. Pollen color: Close to 155D. Pistils: Pistil             quantity per flower: Three. Pistil length: About 3 mm.             Stigma shape: Oval. Stigma color: Close to N82B. Style             length: About 1 mm. Style color: Close to 69D. Ovary color:             Close to 69C.         -   Reproductive organs, sterile flowers.—Stamens: Quantity per             flower: Eight. Filament length: About 3 mm. Filament color:             Close to 75B. Anther length: About 1.5 mm. Anther shape:             Conical. Anther color: Close to 75A. Pollen amount: Scarce.             Pollen color: Close to 155B. Pistils: Pistil quantity per             flower: Three. Pistil length: About 3 mm. Stigma shape:             Oval. Stigma color: Close to 77A. Style length: About 1 mm.             Style color: Close to 75B. Ovary color: Close to 69C.         -   Seeds, only produced by fertile flowers.—Quantity per             fertile flower: About 20 to 30. Length: About 0.5 mm.             Diameter: About 0.1 mm. Color: Close to 200C. -   Pathogen & pest resistance: Under commercial production conditions,     plants of the new Hydrangea have not been observed to be resistant     to pathogens and pests common to Hydrangea plants to date. -   Temperature tolerance: Plants of the new Hydrangea have been shown     to be tolerant to temperatures ranging from about 3° C. to about 38°     C. 

It is claimed:
 1. A new and distinct Hydrangea plant named ‘H217905’ as illustrated and described. 